Metric exposure and custom metrics¶

JMXFetch¶

When DDTrace is run in agent form, the user does not need to specifically open the jmx port. If the port is not opened, the agent will randomly open a local port.

JMXFetch collects metrics from the JMX server and sends them out in the form of a statsD data structure. Itself integrated in dd-java-agent.

By default, JVM information will be collected: JVM CPU, Mem, Thread, Class, etc. Specific metric set list

By default, the collected indicator information is sent to localhost:8125. Make sure turn on statsd collector is enabled.

If it is a k8s environment, you need to configure StatsD host and port:

DD_JMXFETCH_STATSD_HOST=datakit_url
DD_JMXFETCH_STATSD_PORT=8125

You can use dd.jmxfetch.<INTEGRATION_NAME>.enabled=true to enable the specified collector.

Before filling in INTEGRATION_NAME, you can check Default supported third-party software

You can use dd.jmxfetch.<INTEGRATION_NAME>.enabled=true to enable the specified collector.

Before filling in INTEGRATION_NAME, you can check Default supported third-party software

For example tomcat:

custom metrics¶

-Ddd.jmxfetch.tomcat.enabled=true

How to collect metrics through custom configuration¶

How to collect metrics through custom configuration.

• jvm.total_thread_count
• jvm.peak_thread_count
• jvm.daemon_thread_count

dd-java-agent has built-in these three indicators starting from v1.17.3-guance, and no additional configuration is required. However, other MBean indicators can still be configured in this customized way.

Custom indicators need to add configuration files:

1. mkdir /usr/local/ddtrace/conf.d, Other directories can be used.
2. Create a configuration file under the folder guance.d/conf.yaml.
3. conf.yaml at end of doc.

My service name is tmall.jar and the merged startup parameters are:

java -javaagent:/usr/local/dd-java-agent.jar \
  -Dcom.sun.management.jmxremote.host=127.0.0.1 \
  -Dcom.sun.manaagement.jmxremote.port=9012 \
  -Dcom.sun.management.jmxremote.ssl=false \
  -Dcom.sun.management.jmxremote.authenticate=false \
  -Ddd.jmxfetch.config.dir="/usr/local/ddtrace/conf.d/" \
  -Ddd.jmxfetch.config="guance.d/conf.yaml" \
  -jar tmall.jar

The conf.yaml configuration file is as follows:

init_config:
  is_jmx: true
  collect_default_metrics: true

instances:
  - jvm_direct: true
    host: localhost
    port: 9012
    conf: 
      - include:
          domain: java.lang
          type: Threading
          attribute:
            TotalStartedThreadCount:
              alias: jvm.total_thread_count
              metric_type: gauge
            PeakThreadCount:
              alias: jvm.peak_thread_count
              metric_type: gauge
            DaemonThreadCount:
              alias: jvm.daemon_thread_count
              metric_type: gauge